Originally Posted by jsmih

Different break down of the text:

... upon reasonable notice and a finding by the chief executive officer that a need exists, upon any lands, waters, and premises adjacent to the WMATA Rail System, including, without limitation, property owned or occupied by the federal government,

Translation: if the CEO decides to, and they give notice, they can go on any premises adjacent to the rail system, whether privately, state, or federally owned. Nothing limits the access rights being granted to just federally owned property.